School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)

Models struggle against strong wind before the rehearsal of Christian Dior's Haute Couture Spring-Summer 2017 live show to celebrate Dior's new flagship store on the rooftop of Ginza Six mall in Tokyo, Japan, April 19, 2017. (Photo by Toru Hanai/Reuters)

Participants perform a dragon dance as they march during a lantern parade marking the start of a month- long “Lotus Lantern Festival” to celebrate the upcoming Buddha' s birthday, in Seoul on April 29, 2017 Buddha' s birthday falls on May 3. (Photo by Ed Jones/AFP Photo)

The new wax figure of American singer Jennifer Lopez is unveiled on May 21, 2003 at Madame Tussauds, London. The waxwork is the first ever blushing figure. (Photo by Bruno Vincent/Getty Images)

Alice Bagnoli of Italy slaloms during the preliminary round of the 2023 IWWF World Waterski Championships at Sunset Lakes October, 13, 2023 in Lake County, Florida. (Photo by Johnny Hayward/Getty Images)

A cat, named “Sulo”, is seen in Istanbul's Sultanahmet Square wearing sunglasses, in Turkiye, on December 30, 2022. (Photo by Murat Sengul/Anadolu Agency via Getty Images)

Staff members for U.S. Sen. Jeanne Shaheen (D-NH) push a stuffed moose into their office on Capitol Hill on June 11, 2024 in Washington, DC. A stuffed moose named “Marty the Moose” and a stuffed bear named “Kodak the Bear” will be on display in Shaheen's office as part of the thirteenth annual Experience New Hampshire event. (Photo by Andrew Harnik/Getty Images)

“Dover Castle is a medieval castle in the town of the same name in the English county of Kent. It was founded in the 12th century and has been described as the “Key to England” due to its defensive significance throughout history. It is the largest castle in England.

The outbreak of the Second World War in 1939 saw the tunnels converted first into an air-raid shelter and then later into a military command centre and underground hospital. In May 1940, Admiral Sir Bertram Ramsey directed the evacuation of French and British soldiers from Dunkirk, code-named Operation Dynamo, from his headquarters in the cliff tunnels”. – Wikipedia

Photo: The Repeater Station in the subterranean tunnels underneath Dover Castle, which has been restored by English Heritage for a public exhibition on June 3, 2011 in Dover, England. The evacuation of allied soldiers from Dunkirk was masterminded and co-ordinated from the secret command and control centre in the tunnels deep below the castle. (Photo by Matthew Lloyd/Getty Images)